电镀法制备CoNiMnP永磁薄膜研究

采用电子能谱仪(EDS)与振动样品磁强计(VSM),研究了电流密度及镀液pH值对电镀CoNiMnP永磁薄膜矫顽力的影响。结果表明:CoNiMnP永磁薄膜具有明显的垂直各向异性,且随电流密度和镀液pH值的增大,CoNiMnP薄膜的矫顽力呈先增大后降低的变化;当电流密度为5×10–3A/cm2、镀液pH值为5时,CoNiMnP薄膜垂直方向的矫顽力Hcj达到最大值80kA·m–1。     

Physical,structural and topographical aspects of Zn1−xCoxSe thin films

In the present study, Zn_1−xCo_xSe (0≤x≤0.275) thin films were synthesized via a chemical route and characterized through the physical, compositional, structural and morphological properties. The change in colour appearance from ash-grey to charcoal-black suggested integration of Co²⁺ into ZnSe host lattice. Similar conclusions on the colour appearance were drawn from colorimetric studies. The hydrophobic nature of the as-obtained sample surface was revealed in wettability measurements. Zn²⁺, Co²⁺ and Se^2- states of constituents in the thin films were found in the elemental analysis. Formation of ternary alloy was confirmed by shift in (111) X-ray diffraction peak. The surface topography was analysed by an atomic force microscopy (AFM). A variety of AFM parameters were determined to study the effect of Co²⁺ addition onto the surface topography. Magnetic mapping of the surface topography concluded the existence of magnetic domains of irregular sizes and shapes.     

Fabrication of organic semiconductor crystalline thin films and crystals from solution by confined crystallization

Highly crystalline thin films of organic semiconductors processed from solution for electronic devices are difficult to achieve due to a slow and preferential three-dimensional growth of the crystals. Here we describe the development of a processing technique to induce a preferential two-dimensional crystalline growth of organic semiconductors by means of minimizing one dimension and confining the solution in two dimensions into a thin layer. The versatility of the process is demonstrated by processing small molecules (TIPS-pentacene and C₆₀) and a polymer (P3HT), all from solvents with a relatively low boiling point, to obtain crystalline thin films. The thin films show an improved in-plane packing of the molecules compared to films processed under similar conditions by spin coating, which is beneficial for the use in organic field-effect transistors.     

电子束蒸发制备掺钕钇铝石榴石薄膜特性研究

硅基光电集成技术是当代高速信息化的重要发展方向之一。为了研究制备在硅衬底上的新型发光材料,突破Nd:YAG固体激光工作物质主要是晶体、透明陶瓷等固体形态的限制,采用电子束蒸发沉积工艺,在硅(100)衬底上制备了Nd:YAG薄膜,并对Nd:YAG薄膜的表面形貌、晶体结构、光学特性进行了测试。X射线和扫描电子显微镜测试结果显示,Nd:YAG薄膜经1100℃真空高温退火处理1h后有效结晶,采用钛蓝宝石激光器输出808nm激光激发,液氮冷却的InGaAs阵列探测器室温下得到Nd:YAG薄膜的1064nm主荧光峰的荧光光谱。结果表明,采用电子束蒸发沉积和后续高温退火工艺可以在硅衬底上制备Nd:YAG晶体薄膜。     

热蒸发紫外LaF3薄膜光学常数的表征

薄膜光学常数的精确测定对于设计和制备多层薄膜具有重要意义。在JGS1型熔融石英基底上,采用热蒸发沉积方法制备了不同厚度的LaF3单层薄膜样品,利用光度法来获取弱吸收薄膜和基底的光学常数,计算得到其在185～450nm范围内折射率n和消光系数k的色散曲线。实验结果表明,当膜层厚度较薄时,LaF3薄膜折射率表现出不均匀性现象。随着薄膜厚度的增加,薄膜折射率不均匀性减小。在求解过程中选用不均匀模型后,拟合结果与实际测试光谱曲线吻合得很好,提高了薄膜光学常数的计算精度。     

测量薄膜厚度的数字叠栅技术

现代干涉测试的核心是用合理的算法处理干涉图而获得所需的面形及参数。由于常见的相移法要通过移相器有规律地移动采集多幅干涉图并数字化后求取波面的相位分布,这样必然引入由于移相器的线性及非线性误差所带来的计算误差,因此需要事先对移相器进行标定。采用了数字叠栅方法,利用一幅静态干涉图与一个正弦光栅的四幅光强分布图叠加,从而实现相移式动态干涉测试的效果,借助于相移法处理干涉图原理,可获得波面相位分布,从而实现对薄膜厚度的测量。由于正弦光栅的初始相位是由计算机产生的,所给出的相位移动不含任何移相误差,因此可提高测量的精度。     

Co/BaTiO3纳米复合薄膜的PLD法制备及其Raman光谱

采用脉冲激光气相沉积（PLD）技术在MgO（100）衬底上生长了Co/BaTiO₃纳米复合薄膜,利用原子力显微镜、透射电镜、X射线衍射（XRD）及Raman光谱等测试分析手段对Co/BaTiO₃纳米复合薄膜进行测试分析。结果表明：薄膜表面均匀、致密,具有原子尺度的光滑性;Co纳米晶粒呈单分散、均匀分散在沿C轴呈单取向生长的BaTiO3单晶基体中;随着掺杂Co含量的增高,BaTiO3的Raman峰的峰强随之增大。     

用磁控溅射和退火方法制备AlSb多晶薄膜

采用磁控溅射法在玻璃衬底上制备Al/Sb预制多层薄膜,然后将Al/Sb预制多层薄膜在退火炉中退火得到AlSb多晶薄膜.用X射线衍射(XRD)法测薄膜结构;用扫描电镜(SEM)测薄膜Al/Sb成分比,结果表明AlSb多晶薄膜具有单一的晶相、均匀的结构,以及粒径大约20nm的晶粒.根据电导率(lnσ)与温度(T)的关系得到电导激活能为0.21和0.321eV,为制备出适用于太阳电池的AlSb多晶薄膜奠定了一定的技术基础.     

均匀设计法研究PZT铁电薄膜制备工艺的优化

应用射频磁控溅射工艺在Pt/Ti/SiO2/Si衬底上制备具有钙钛矿结构的PZT铁电薄膜。对影响PZT薄膜性能、形貌的工作气压、基片温度、氧/氩 氧之比、溅射功率、退火温度5个主要因素进行分析,在其允许范围和精度内设置5个水平,并根据均匀设计理论对该5因素及5水平进行均匀设计。不同温度下退火之后测定了PZT薄膜的厚度、SEM表面形貌、电容、介电损耗、电滞回线(包括矫顽场强、饱和极化强度、剩余极化强度)等。最后对响应结果进行多元二次线性回归,得出了回归方程。探讨达到最优化薄膜特性所需要的工艺条件。